SiO2 wrote: I doubt any custom developer would try to mess with animation or something.
I don't want to discourage anyone from reporting issues. However, just because they don't mess with it (or do) doesn't mean that what has been changed can't cause issues in strange ways. If you can't confirm it (or won't) with the standard client, take it up with the other guy first. They know better what they have and haven't done and might be able to point loftar at where they think the problem is. If they can't figure it out, loftar has shown to be as helpful as possible.
SiO2 wrote: hitbox is not shown by the client, but the character can actually hit it by walking in.
Amber et al only show hitboxes for objects rendered to screen. If for some reason the client isn't being told to render this object, then the client can't render a hitbox.
There may be a client problem, it might be a client/server communication error. It's hard to say. Obviously the server thinks you're in combat and allows you to interact with the object.
To note, Im pretty sure this has come up before. It might take some deep digging to find it (because people can't create good titles for some reason.) Updated this title.
Troubleshooting suggestion: can you see it via the minimap? If so, you should be able to always interact with it this way similar to animals that are stuck underwater. (Thought: object might be rendering "under the surface" of the world for some reason.)
Opinions expressed in this statement are the authors alone and in no way reflect on the game development values of the actual developers.